The emergence of the People’s Republic of China as an increasingly significant military power in the Western Pacific presents major implications for Japan, the U.S.-Japan alliance, and regional security. But a comprehensive assessment of the current and possible future impact of China’s military capabilities and foreign security policies on Tokyo and the alliance, along with a detailed examination of the capacity and willingness of both the United States and Japan to respond to this challenge, is missing from the current debate. Such an analysis is essential for Washington and Tokyo to better evaluate the best approaches for maintaining deterrence credibility and regional stability over the long term.

KEY FINDINGS

The most likely potential challenge to the U.S.-Japan alliance over the next fifteen to twenty years does not involve full-scale military conflict between China and Japan or the United States—for example, one originating from Chinese efforts to expel Washington from the region.

The likeliest challenge instead stems from Beijing’s growing coercive power—increasing Chinese military capabilities could enable Beijing to influence or attempt to resolve disputes with Tokyo in its favor short of military attack.

An increase in the People’s Liberation Army’s presence in airspace and waters near Japan and disputed territories could also heighten the risk of destabilizing political-military crises.

Significant absolute and possibly relative shifts in the military balance between China and the alliance in Japan’s vicinity are likely.

In the most probable future scenarios facing these three actors, the U.S.-Japan alliance will either only narrowly retain military superiority in the airspace and waters near Japan or the balance will become uncertain at best.

A significant drop in the potential threat posed by China is also possible if the Chinese economy falters and Beijing redirects its attention and resources toward maintaining internal stability.

More dramatic shifts in the strategic landscape are unlikely in the fifteen- to twenty-year time frame. Such shifts include an Asian cold war pitting a normalized U.S.-Japan alliance against a belligerent China and a major withdrawal of U.S. presence that heralds either the dawning of a Sino-centric Asia or the emergence of intense Sino-Japanese rivalry with Japanese nuclearization.

U.S. AND JAPANESE POLICY RESPONSES

There are no “silver bullets.” No regional or alliance response can single-handedly deliver a stable military or political balance at minimal cost to all parties involved. Each of the major conceivable responses to these future challenges in the regional security environment will likely require painful trade-offs and, in some cases, the adoption of radically new ways of thinking about the roles and missions of both the U.S. and Japanese militaries.

Three general political-military responses offer viable ways to advance allied interests over the long term.

Robust Forward Presence: This deterrence-centered response is designed to retain unambiguous allied regional primacy through either highly ambitious and forward-deployment-based military concepts, such as Air-Sea Battle, or approaches more oriented toward long-range blockades, such as Offshore Control.

Conditional Offense/Defense: This primacy-oriented response nonetheless avoids both preemptive, deep strikes against the Chinese mainland or obvious containment-type blockades and stresses both deterrence and reassurance in a more equal manner.

Defensive Balancing: This response emphasizes mutual area denial, places a greater reliance on lower visibility and rear-deployed forces, and aims to establish a more genuinely balanced and cooperative power relationship with China in the Western Pacific.

These responses could be complicated by a number of factors.

Limits on the ability of Japan or other nations in the Asia-Pacific region to advance substantive security cooperation or embark on major security enhancements

Unwillingness in the U.S. military to alter doctrinal assumptions in operating in the Western Pacific China’s own suspicions of alliance efforts that might constrain the use of its growing capabilities

Low tolerance among stakeholders for uncertainty and even failure during political or diplomatic negotiations over vital security interests

The status quo is likely to prove unsustainable. Despite the potential complications, Washington and Tokyo must seriously evaluate these possible responses. Current economic and military trends in China, Japan, and the United States suggest that existing policies and strategies might fail to ensure a stable security environment conducive to U.S. and Japanese interests over the long term. …